The present disclosure relates to devices in the field of measurement equipment, in particular to indicating, recording and signaling devices actuated by electrical means. The device may be used as a sensor for detecting the leakage of water or other conductive fluids regardless of whether they are in a liquid state or whether they are able to conduct electricity.
Water and other fluids delivered through pipes held in reservoirs and containers play an important role in human society. When water is flowing in the manner intended and stays within its designated containers, water does great things for human civilization and modern life. But when water leaks from designated containers and delivery devices such as pipelines, it is a force for destruction. Most destructive and problematic in modern commercial and residential buildings is when water leaks from pipelines. The nature of these leaks makes them difficult to detect. Without adequate leak detection there cannot be a proper remedy. The effect of a small leak cumulated over time often results in significant damage that could have been mitigated if the leak had been detected earlier. The most troublesome of leaks occur in spaces and surfaces that are not typically accessible or open to monitoring. An example is the network of pipelines behind dry-wall or concrete walls of commercial and residential buildings. The point of leakage can be anywhere within the system and there is a significant amount of surface area that must be covered. Furthermore, the location or position at which a leakage sensor can be mounted significantly constrains the device. For example, for a horizontally placed pipeline, the leakage is likely only to be detectable at the bottom of the pipeline and as such it must be mountable upside-down on the bottom of the pipeline.
Another problem in water leakage detection is that the water is not always in a liquid state. In certain environments, the water is in a non-liquid or gaseous state such as water vapor or steam. Yet in other environments, the water leakage can occur in the form of water in mixed states—i.e., where the water can manifest as a liquid or as steam.
Yet another problem in water leakage detection is that water is not always able to conduct electricity. Water in certain environments (e.g. water used for cooling in data centers) is chemically clean and fully deionized. Where the water is purified to 99.99999991% degree of purification, the electrical resistance of water can be increased up to 18 mega-ohms-cm, making the water non-conductive.
Therefore, there is a need for a device capable of the sensitive detection of the leakage of water and fluids in various states and in various degrees of conductivity mountable on many types of locations and surfaces.
An example of an attempt at designing such a device is disclosed in Russian Patent No. RU 2312954 [C1, E03C 1/00, F24D 19/10, Dec. 20, 2007]. This device comprises a horizontal perforated plate, a water level sensor, a siphon and a tank with an open top where the dimensions of the tank's horizontal section is smaller than the dimensions of the perforated plate. The tank is attached underneath the perforated plate and is shifted to the edge. The tank has a hole at its bottom. The water sensor and the siphon are placed inside the tank such that the siphon's fold is located above the water level sensor. The holes on the perforated plate are positioned in such a way that at least one of them is located above the tank. The perforated plate has ribs that are arranged on the top part of the perforated plate, which forms a closed contour surrounding all the holes, except for those located above the tank, or the groove forming a closed contour surrounding all the holes except for those that are located above the tank, and on one hole the groove closes. The disadvantage of this device is its relatively narrow functionality, which in turn restricts its application for lengthy objects such as pipelines.
Another example of an attempt at designing such a device is disclosed in Russian Patent No. RU 25222 [U1, G01M 3/10, G01M 3/26, Sep. 20, 2002]. This device comprises a tank and a sensitive element posted therein, which is made in the form of a rod on which the following elements are mounted: a high-precision ultrasonic detector of a product level fluctuation, temperature gauges, a bottom water level sensor and an electronic unit connected to a computer that provides a software computation of interdependency of fluid temperature layers and the fluid level. The disadvantage of this device is its relatively narrow functionality, as it is designed for leak detection from reservoirs, and its application for extended objects, e.g. pipelines, is functionally restricted.
Another example of an attempt at designing such a device is disclosed in Russian Patent No. RU 99156 [U1, G01M 3/10, G01M 3/26, Nov. 10, 2010]. This device is an automatic electronic water sensor. It comprises a protective tube with a center pad made of intrinsically safe metal with built-in end electrodes hardwired to an electronic indicator. The electronic indicator contains an electronic circuit, a LED, and a buzzer connected to a power supply source and is dash-mounted. The disadvantage of this device is its relatively narrow functionality, as it is designed to indicate the presence of water in the tank without the ability to detect the location of the water leakage, which in turn restricts its application for lengthy objects such as pipelines.
Yet another example of an attempt at designing such a device is disclosed in Russian Patent No. 2545485 [C1, G01F23/18, Apr. 10, 2015]. This device includes two conductors, each in the form of at least one conductive wire, connected to an electronic indicator, wherein the electronic indicator is designed as a resistance meter. Each conductor is placed in a conductive coating made of a conducting polymer compound. A single water-permeable shell made of a capillary-porous material is located between and around the conductive coatings. One feature of this device includes that of a conductive polymer compound used for the conductive coating, which may be based on polyolefin and carbon soot in the ratio from 4:1 to 1:3. Another feature is the use of a twisted fiber glass filament or fiberglass roving that can be used as the water-permeable shell made of a capillary-porous material. The conductive coating made of a conductive polymer compound is designed to have a surface resistance Rs in the range of 1 to 103 Ohm. During manufacturing, it is possible to select various different compositions of the conductive polymer compound, as long as the surface resistance of the conductive coating layer achieves a surface resistance value between the range of 1 to 103 Ohm; the water-permeable shell made of a capillary-porous material is either in the form of a complete extended structure or in the form of a harness of a capillary-porous fiber wound around the conductors, which are placed in the conductive coatings made of a conductive polymer compound with a path in the form of closed eights. The disadvantage of this device is its low sensitivity, which is due, in part, to the relatively small size of the extended area of the water permeable shell made of a capillary-porous material. Moreover, this device is incapable of detecting deionized water, making it useless in environments where deionized water is being delivered.